Abstract:
A luminaire can comprise a system that automatically adjusts light output from the luminaire to control light level in an illuminated area. The system can increase light output if the light level in the area falls below a target light level or decrease light output if the light level in the area rises above the target. For example, when the area is illuminated by a combination of sunlight and luminaire light, the light level can be maintained at the target level by gradually decreasing light output as the sunlight contribution increases in the morning and by gradually increasing light output as the sunlight contribution decreases in the evening. The system adjustments can take into consideration whether the light level is offset from the target due to a change in the target or a short-term fluctuation that may be due to a cloud temporarily blocking the sun.
Abstract:
Multiple signals are received from multiple receivers in a motion sensor. Each signal is amplified and undergoes a gain adjustment individually to generate multiple preamplified received ultrasonic signals. A separate demodulator circuit receives a different preamplified received ultrasonic signal and generates a sum of the demodulated signals and a difference between the demodulated signals. A low pass filter corresponding to a demodulator circuit removes the sum of the demodulated signals. The mixer circuit combines the difference between the demodulated signals to generate an integrated circuit. The gain of each preamplifier may be adjusted based on a sensitivity setting, target levels of the preamplifier, and a level of a preamplified ultrasonic signal, resulting in an integrated motion sign that originated from multiple signals to different receivers in the sensor housing.
Abstract:
A device for operating a relay to selectively provide power from a power supply to a load. The device determines an activation switching point for activating the relay such that inrush current resulting from the activation is minimal. The device also determines a deactivation switching point for deactivating the relay such that backrush current is minimal. The switching points are determined with respect to a voltage waveform of the supply power. The device varies the timing of the operation of the relay with respect to the voltage waveform and monitors the inrush or backrush current resulting from each timing until a minimum inrush or backrush current is found. The device stores these times in memory for subsequent operation of the relay. To further reduce inrush and backrush currents associated with inductive loads, the device activates and deactivate the relay on opposite half cycles.